


(No such thing as) The greater good

by Askellie (NadaNine)



Category: Undertale (Video Game)
Genre: Abduction, Accidental Stimulation, Aftercare, Angst, Captivity, Drugs, Electricity, Hurt/Comfort, M/M, Medical Experimentation, Multi, Non-Consensual Body Modification, Non-Consensual Bondage, Overstimulation, Rape/Non-con Elements, Soul Penetration, Soul Sex, underswap - Freeform
Language: English
Status: Completed
Published: 2018-01-17
Updated: 2018-01-17
Packaged: 2019-03-06 06:04:39
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 6,163
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13405008
Author URL: https://archiveofourown.org/users/NadaNine/pseuds/Askellie
Summary: The doctor turned to Sans, an expression of distaste on his otherwise stern features. “Your brother would have been a superior candidate for the procedure, but this replacement you’ve chosen will suffice.”Sans's old boss comes back from the Void, freshlydeterminedand ready to science. Stretch isn't the perfect test subject, but with a bit of modification he could be.





	(No such thing as) The greater good

**Author's Note:**

  * For [Ravvi](https://archiveofourown.org/users/Ravvi/gifts).



> This was a Secret Santa gift for Ravvi-k, who is one of my very favourite authors and writes pretty much the best non-con medical kink around. This is my tribute to their amazing talent.

“I’m sorry. I’m so sorry, Stretch.”

The words hazily penetrated the comfortably muzzy haze Stretch was immersed in. Like a distant alarm clock, the sound nagged for his attention, jarring him from pleasant unconsciousness.

“Hnnnnuuuh?” He tried to voice a query, but all that came out was a weak croak, barely audible. His jaw and throat tingled oddly, like when his magic wasn’t circulating properly and the threads holding his bones in place threatened to fray. His skull felt full of cotton, worse than the nights he couldn’t sleep and the deep bite of exhaustion weighed so heavily on him he couldn’t concentrate or will himself to move. He might have dismissed that quiet apology altogether and let himself drop back into sleep except at that moment he felt his body give a heaving, unpleasant jolt.

“Uuhnn?” He was...upside down? Slung unevenly over someone’s shoulder, his face pressing into their back. The ground wasn’t very far away though. He could practically reach out and touch it; whoever was carrying him was much shorter than he was.

“F-fuck-!” The world tilted dangerously as they both nearly toppled. Whoever was holding him didn’t seem to have a great deal of strength or balance, which eliminated Blue (whose guard training made him stronger than Stretch himself) and Red (who was more broad and sturdy) so...Sans?

That seemed right. He vaguely remembered Sans had come over and there had been talking and punning and honey. Maybe too much honey? Was that why he felt weird? Normally he wouldn’t have overindulged at home where Blue might see and disapprove, but they didn’t seem to be in his bedroom anymore. They were outside. It was dark and faintly damp, which his hazy mind eventually connected to guess they were in Waterfall. Had Sans dragged him out so Blue wouldn’t catch them? What a great pal.

...although that didn’t explain why he was apologising. Huh.

Sans was staggering forward, his gait uneven and nearly teetering under Stretch’s weight. Stretch tried to pat his back to get his attention, thinking to tell Sans that he didn’t need to worry about it and that Blue probably wouldn’t think to look for them here, but his clumsy swat seemed to startle Sans. He tripped, nearly sending them both crashing to the ground. He barely managed to ease them both down, heaving Stretch off his shoulder and propping him up against the nearby wall. Stretch blinked at him bemusedly, confused by the sweat and stress he could see on Sans’s face. It was the first time he’d ever seen the easy-going skeleton so worked up. He wanted to lift a hand to Sans’s shoulder in comfort and ask him what was wrong, but his bones felt strangely leaden, even more so than what inebriation usually caused.

“W-why are you awake already?” Sans asked, although he seemed to be speaking to himself rather than Stretch. With a quiet curse he fumbled around inside his hoodie pocket, pulling out a bottle of honey.

_“Got it from the Fell-verse,” Sans told him with an exaggerated hitch of his brow-bones, like he was delivering a sly secret. It kind of was; trading luxuries between the universes was not only a questionable moral dilemma, but a potential threat to the overall stability of the timelines. It took a bit of careful cheating and balancing to smuggle things in and out. “I hear it’s got a bigger kick than what we’re used to. Figured you’d want to try it.”_

_“Nice,” Stretch said, eagerly reaching for the treat, trying to pretend his soul wasn’t fluttering absurdly because Sans had brought him a gift, had bent the rules of time and space just to treat him. They all tried to be good to each other -- all the versions of himself and his brother -- but sometimes he worried he hadn’t really earned Sans’s affection, he’d just inherited it from being tangentially related to Papyrus. It was flattering to feel singled out because of who he was, not who he could have been in some other universe._

_Too aware of Sans’s eyelights watching him, Stretch twisted open the jar and took a generous gulp. He only barely managed to control his reaction, magic surging in his mouth and taste buds tingling unpleasantly. It had a kick, certainly, but there was something a little off too. A flavor that was sharp and harsh, like battery acid; something that tasted foreign in the honey. Was that the Fell-verse difference?_

_“It’s great,” he lied, not wanting to offend, and certainly not wanting Sans to think he was ungrateful. It wasn’t his fault if Fell-verse honey sucked. Gamely, Stretch took another sip, swallowing it down quickly so the taste wouldn’t linger. Something about that biting flavor was making his skull feel fuzzy…_

The open jar was pressed against his teeth, and Stretch weakly turned his head away. It must have been the honey that was making him feel weird, slow and sluggish and disoriented, so he really shouldn’t have any more of it. He was starting to regret telling Sans he’d enjoyed it.

And Sans should know better, anyway. If Stretch wasn’t coherent, he definitely should’t be indulging in illicit condiments. He tried to tell Sans so, opening his mouth to protest, but all that came out was an unintelligible moan and parting his teeth gave Sans an opportunity to tip a glob of honey over Stretch’s tongue. The contact burned with that strange, unsettling fizzle, and what little cognizance he’d gained started to evaporate again.

It only occurred to him on the very verge of unconsciousness that Sans’s actions were deliberate. The hands holding the jar to Stretch’s mouth and tilting his skull to ensure it poured right down his throat, watching intently as Stretch’s sockets sagged, eye-lights stuttering out...he knew exactly what he was doing.

_What_ **_was_ ** _he doing?_

He wanted to ask the question, but didn’t even manage to gurgle the first syllable before the numbing prickle of the honey spread from his mouth to his skull, and his awareness faded out completely.

* * *

 

It felt like both a smothering eternity and a panicking instant before Strecth finally came back to himself. His skull throbbed with a low ache that might have matched the hangover he’d thought he should have if he hadn’t been newly certain that there had been something else in the honey Sans had given him. He blinked rapidly, trying to clear his foggy vision, and found himself staring up at a bright, white overhead light embedded in a metal plated ceiling. The air smelled stale with a hint of disinfectant that almost reminded him of the lab, but it didn’t smell like salt and sushi the way Undyne’s lab did.

...but Undyne wasn’t the royal scientist in every timeline. Was this a different lab? The one from Sans’s timeline, maybe?

He could feel a pinching discomfort across his jawbone that he almost dismissed as a lingering effect of whatever drug had been in the honey, but when he tentatively conjured his tongue to explore the sensation, it came up immediately against a hard, rubber protrusion that had been forced between his teeth. He choked in surprise, spluttering around the broad, rounded plug that very thoroughly filled up his mouth, stifling his surprised grunt. Pushing his tongue against it and trying to loosen his mandible revealed that it was strapped around his skull, impossible to remove without intervention.

He tried reaching up to yank at it, only to become belatedly aware of similar pinching at his wrists and ankles. He could barely twist in place to examine himself, but from what little he could see, thick straps held him restrained and almost immobile flat on his back. He squirmed experimentally, but none of the bonds gave any sign of weakness or leniency.

“Ah. You’re awake.”

Stretch jumped in surprise, although the movement was pulled up painfully short. He was still shaking off the effects of sedation, and hadn’t noticed the stranger looming in the corner of his vision. They blended in well with the surroundings, their stark white lab coat and bone-pale face not providing much contrast against the blank walls. He looked like a skeleton, though his features didn’t match any of the alternates Stretch was familiar with. His gaunt face was riven by two thick cracks, one extended from above his right eye-socket and the other descending from his left, cleaving through his cheek to the bottom of his jaw.

Stretch bucked against his restraints, making an urgent sound, but the skeleton ignored him, picking up a nearby clipboard and jotting down some notes.

“Effects of the administered sedative are wearing off within the predicted time frame,” the skeleton noted aloud. They raised their index finger and ran it back and forth across Stretch’s field of vision. Stupidly, his eyelights followed the movement; right, left, right. “Subject is awake and cognizant of his surroundings.”

_Subject?_ Stretch tried to voice a question but the gag stifled his attempt at speech. As more awareness returned, the unsettling reality of his position hit him. He was strapped solidly to the hard plane of a metal table. The cold of the sterile surface seeped into his spine, making his nakedness uncomfortably evident. He squirmed with only discomfort at first, then with rising panic. He couldn’t sit up, couldn’t cover himself from the unknown skeleton’s invasive gaze, and the helpless way he was splayed out, gagged and immobile, filled him with anxious dread.

How long had he been unconscious in this position? There was already a straining ache in his jaw that only worsened when he clenched his teeth around the gag. He bit down hard, trying to find some way to compress the rubber to let a more coherent sound slip past, but all he managed was an incoherent gurgle of confusion that didn’t even capture the other skeleton’s attention.

The sound of a door opening certainly drew Stretch’s though. He whipped his head to the side, arching his body to try and glimpse the source of the sound. He couldn’t quite contort himself far enough, but after a few moments Sans stepped into his peripheral vision.

“Sorry I’m late,” Sans droned flatly, his body visibly sagging with exhaustion and some other, less definable weight.

“HNN!” Stretch forced a desperate, relieved sound past the gag. _FINALLY_. Someone who could tell this unsettling doctor to release Stretch from the table and treat him like a proper monster instead of a test subject...but despite his urgent writhing and huffing Sans didn’t even look at him. His gaze was focused lifelessly on the floor, eyelights so faint Stretch could barely discern them from the darkness of his sockets.

“Hnn?” Stretch tried, much less certainly, his soul clenching with painful unease.

“Finally. I was just about to begin,” the doctor intoned, pushing a medical cart holding a strange piece of machinery towards the table. “You can start by attaching the sensors. I’ll configure the machine.”

Wordlessly, Sans moved to comply. He seemed completely oblivious to Stretch’s imploring stare, avoiding making eye-contact as he worked to untangle an assortment of long wires. Each ended in a round, circular pad of what Stretch discovered to be sticky gauze as Sans began to attach them methodically to his bones. Even though Sans worked with nothing more than clinical efficiency, Stretch felt a surge of embarrassment as the pads were adhered to the more intimate parts of his body. His face flushed hotly when Sans’s hands delved into his rib cage to stick the sensors to the inside of this spine and the underside of his sternum, and he squeaked with humiliation when more pads pressed against the bowl of his pelvic cavity.

The wires trailed over his body from his temples to the soles of his feet, an unfamiliar and ticklish intrusion. Stretch tried yanking at the restraints again, hoping to find some sliver of leeway, but all he accomplished was chafing the bones of his carpels against the leather. His unhappy whimper went ignored by the other two monsters.

“Ready,” Sans muttered, stepping back once he was satisfied the last sensor was in place.

The doctor flicked a switch on the machine. Its low hum grew to an aggressive buzz of preparation. A nervous sweat began trickling down Stretch’s skull as he eyed the strange device warily.

“Taking the first reading now,” the Doctor announced, and pressed another button. A new sensation jolted through the pads, rippling through Stretch’s body with an unnatural tingle. Stretch convulsed, bones quivering. It wasn’t painful per se; it felt like the first time Red had taken him to the Underfell incarnation of Grillby’s. The moment they’d walked through the door, every patron in the room had Checked him simultaneously, scoping out what sort of threat he represented. This felt similar, like dozens of eyes boring into his body and soul, analysing and judging him. He felt helplessly exposed, his sense of nakedness twisting into a shame so poignant he could feel tears prickling up inside his sockets. He valiantly fought them back, trying to focus on the haphazard hitches of his breath, trying to ease it back into a less panicked rhythm.

What were they doing? Why was Sans allowing this? Surely he could tell Stretch was uncomfortable and not at all on board with this treatment. It certainly didn’t seem like it was something they were doing for his benefit, so he doubted there was any justifiable excuse, medical or not, to have him bound and gagged like this while they probed his body with their machine.

The machine’s pervasive hum receded to a more tolerable level, and the discomforting scan abated, allowing Stretch to relax fractionally. The doctor was staring intently at a different facet of the machine, the light cast on his face indicating there must have been a screen there.

“Medial Mana lines show an average diameter of thirty-seven microns. Results are indicative of an infrequent utilisation of strenuous mana usage, resulting in minimal dispersal of the circulatory veins and an underdevelopment of the vessels. Adjustments will be made to the procedure to account for the 20% discrepency between the current subject’s physiology and those of former subject P-2 in order to achieve successful results.”

The doctor turned to Sans, an expression of distaste on his otherwise stern features. “Your brother would have been a superior candidate for the procedure, but this replacement you’ve chosen will suffice.”

Sans flinched -- the most visible reaction he’d given so far -- and Stretch suddenly realised what leverage the Doctor was using to secure Sans’s co-operation. Sans had deliberately sacrificed him to spare his brother from whatever procedure the Doctor had planned. Aghast, he thought: of everyone he could have chosen to throw under the figurative bus, Sans had chosen _him_?

...did Sans really hate him that much?

“I’ve already prepared the Injector,” the doctor announced, turning away to retrieve something outside of Stretch’s vision. “Summon his soul for me.”

Stretch jerked in shock, turning to stare at Sans with horror. Blue magic made it possible to materialise a monster’s soul outside of battle, but surely he wouldn’t-

**_*TING*_ **

Stretch screeched into the gag, yanking mindlessly against the cuffs to try and rescue his soul and drag it back into the safety of his rib cage, but Sans’s magic gently drew it out of reach until it hovered a foot above his prone body. Sans must have been doing his best to keep his emotions divorced from the situation, but with his magic wrapped about Stretch’s soul Stretch could feel the faint echoes of regret, self-disgust and unease. Not that it mattered to Stretch; he was falling apart because _no one should be touching his soul, no one should be looking at it, oh god_ …

“Shh,” Sans muttered softly, giving Stretch’s arm a brief pat that was probably intended to be reassuring. “It’s fine, you’re fine. It’s gonna be okay.”

“You don’t need to reassure him,” the Doctor said, sounding almost amused. “There’s no evidence to suggest the subject’s state of mind will have any impact on the results of the treatment.”

There was a brief spike of white-hot emotion in Sans’s magic -- something hateful and vile -- before Sans buried it again. His face remained mostly expressionless, but he withdrew his touch from Stretch’s shoulder. Stretch barely noticed. The entirety of his being was focused on his exposed and vulnerable soul as the Doctor cupped his hand around it.

“Condition of the subject’s soul is good. Shape is normal and size is proportional to the host’s body. No evidence of cracks or scarring, nor any kinds of trauma. Illumination is bright and stable, though its pulsation pattern suggests the subject is experiencing a stress response.”

“HNGH!” Stretch grunted, both a protest to the impersonal evaluation and the feeling of cold fingers probing the surface of his soul. The Doctor was wearing gloves, which thankfully shielded him from the intimacy of direct contact, but even without the emotional connection it was terrifying to have someone unknown and untrusted handling it.

His barely restrained trembling turned into a violent convulsion when, without warning, the Doctor pressed firmly into the shallow crease between the two lobed halves of his soul. There was no intent behind it to make the touch painful, but it felt bizarre. Unwanted. _Wrong._

“Preparing subject to accept penetration of the Injector,” the Doctor said, his voice a dim intrusion on Stretch’s growing panic. He knew from his own tentative explorations that the outer surface of his soul would soften with a bit of gentle handling, allowing exploration of the inner layers. It resisted -- stiff with his tension and fear -- but he didn’t know how to make himself immune to the unrelenting physical sensation. Some deeply driven instinct tried to convince him that the handling of his soul was pleasurable no matter how much he didn’t want it to be, and he shuddered uncontrollably, wracked with the urge to relax, to yield and accept.

With one hard push, the Doctor’s thumb pierced through the outer surface of his soul with a slick, lewd sound that made Stretch whine in mortification even as he burned with a shameful heat. His chest was heaving, trying to draw cooler oxygen into his rib cage, but it didn’t help abate the intensity.

“Penetration successful,” the Doctor reported, his tone conveying nothing more than mild interest which felt completely at odds with how vigorously he slipped a second finger into Stretch’s soul. He began scissoring his fingers back and forth, pushing against the inner walls like he was trying to stretch it out. The sensation was mind-blowing, too ruthlessly fast for Stretch to enjoy it, but teetering on a despicable kind of pleasure that utterly confused his senses.

“Now inserting the injector.”

Stretch’s eyes snapped to the Doctor, but instead of a needle like he would have expected from the name, the object being pressed into his soul looked more like a sphere. He didn’t have a chance to properly make out its details before he was suddenly becoming acquainted with it in a far too intimate fashion, his muffled noises reaching a wild peak as its cold, round body was thrust into the space the Doctor’s fingers had previously occupied.

This was what his soul had been stretched for. It was barely large enough to house the foreign object; it distended obscenely around the sphere as he bucked in mindless desperation. He could feel himself losing control over both his body and his magic. He couldn’t stop himself from writhing even though the restraints were starting to chafe painfully against his bones. Magic welled up unbidden inside his mouth in some kind of confused salivary response to the presence of the gag. Worst of all, the unwanted heat condensed in a heavy pressure low in his pelvis, thrumming violently against his bones before suddenly jolting against him with a much more tangible weight.

“Uh...Doc?” Sans sounded perturbed.

There was a brief pause that gave the object in his soul a moment to settle into place. It turned out not to be entirely spherical. There were small, pointed protrusions across its surface that dug uncomfortably into the inner walls of Stretch’s soul, making the aching engorgement of its presence that much more uncomfortable. He felt helplessly and unnaturally full, and he didn’t realise why the sensation felt faintly familiar until something prodded at the underside of his pelvis.

“Subject is exhibiting a sexual response to the presence of the Injector,” the doctor noted blandly. “An unintended but not wholly unexpected side-effect of stimulating the soul.”

“Damnit, G...you could’a warned me that might happen,” Sans grumbled, sounding strangely flustered. “I don’t think we should-”

“Your opinion is not required,” the Doctor cut him off shortly. “The treatment will continue as planned.”

Stretch gasped weakly, his overtaxed senses having difficulty processing the exchange taking place above him. His soul gave a distressed pulse, tightening around the sphere now buried in its depths, and Strtech could feel unfamiliar magic and foreign muscles echoing that clenching movement. He craned his neck, not able to make out much past the swell of his rib cage, but between the light emanating from his pelvis and the intruding pressure filling up his pelvic cavity, he realised that he’d ummoned his ectoflesh in his overstimulated daze. He’d never experimented much with this particular configuration since a cock was much easier to handle and explore than a pussy, and he couldn’t imagine why it had summoned itself except that the bizarre tight-full-pressure of the sphere in his soul was most similar to his own tentative explorations with this set of genitals.

But this entire situation was entirely the wrong environment for a sexual manifestation, and he felt appauled at what his magic had conjured without his consent. He tried to dispel it, but attempting to focus just made his soul give another reflexive squeeze around the sphere, shattering his concentration with a spike of unwanted pleasure-pain. He whined pitifully as his cunt also throbbed in sympathy.

“Start the Injector,” the Doctor ordered Sans curtly. “Begin at the baseline setting. I’ve lowered it to account for this subject’s reduced capacity compared to Subject P2-”

“Papyrus,” Sans interrupted resentfully, scowling in the doctor’s direction, although his gaze briefly skittered over Stretch’s body, making both of them flush. “He _has_ a name.”

“Names create attachment, Sans,” the Doctor scolded. “You will find it easier if you forgo the use of one with this replacement.”

Stretch quivered, his body tense with fear and horror. He tried desperately to catch Sans’s gaze again, to convey as strongly as possible his wordless plea, _NO, PLEASE DON’T_. Even though Sans wasn’t looking directly at him, Stretch thought he saw a moment of hesitation in the way Sans’s hand hovered over the control panel at his side.

“Nnn!” he tried to beg. “Hnn! Nnngh!”

Sans pressed the button.

Stretch’s mind went white-hot. It burned, everything burned. Lightning scalded through his soul, through his limbs, through every inch of him, burning him up from the inside. It was magic, he realised -- too raw and too much, razing through his marrow like an infection. Distantly, he thought he might be screaming. It was a sensation beyond agony; an incomprehensible overload that grew and peaked and-

-released, with a euphoric rush that wracked his body with wave after wave of indescribable pleasure. His soul clenched and gushed with a sudden explosion of fluid that splattered the inside of his ribs, and his pussy followed suit with a trembling spasm that was forceful enough to expel slick streaks across his femurs. The overload abated so suddenly, he wondered if he was going into shock, or maybe even dying. For a moment it had certainly felt that way, although once the aftershocks of unexpected orgasm finally began to pass the pain began to set back in.

His marrow felt like it had been drawn out and replaced with lava. His bones felt like they were being boiled. There was even a sour, smokey smell to accompany the heat, and when his head lolled dazedly to the side, he could see something dark and putrid leaking out from the joint between his humerus, ulna and radius. The faint orange tint to it suggested it might have been his own magic, now corrupted and oozing from his body.

“-successful enlargement of the mana-pathways by a factor of 2.7 percent from a single treatment. Subject’s HP remains stable and stats unchanged, although experiment simulations suggest these may increase as treatment progresses. Additionally, subject appears to have naturally vented the excess of injected magic by achieving climax during the procedure. The majority of the ejaculated material emerged from the soul and genitals, but additional residue has been excreted from major arterial junctions across the body. Successful expulsion of the foreign materiel means that the expected refractory period for the circulatory issue will be significantly reduced, allowing us to continue treatment immediately.”

“Immediately?” Sans echoed weakly, not sounding nearly as enthusiastic as the Doctor did about his findings.

“I see no reason to delay. In fact, it would be ideal to take advantage of the subject’s current condition. His current ability to discharge the magical excess is significantly safer and much more efficient.”

“Safer? I thought you said this procedure _was_ safe!?”

“I said the risk was negligible,” the Doctor corrected. “Naturally there is some risk. We are handling a _soul_ , Sans. Monster souls are innately fragile constructs, as I’m sure you remember from your training.”

“ Fuck you,” Sans spat at him, coldly but firmly.

The Doctor continued, apparently unoffended. “If you’re concerned about the subject’s health, then you can assist in the procedure. Additional stimulation would allow him to reach peak absorption rate more swiftly, and inducing climax will ensure all dangerous excess is quickly expelled from his soul.”

Sans’s hesitation was palpable. “...What do you want me to do, exactly?”

“Do you need instruction, Sans?” There was a dark and decidedly unscientific note of amusement to the Doctor’s voice. He reached across the table in one striking, snake-like movement, grabbing hold of Sans’s defensively raised wrist and yanking it down towards Stretch’s pelvis. “Manual stimulation of the clitoral nerves is probably sufficient, but penetration of the vaginal passage may prove more effective given what we’ve already observed of the subject’s reactive behaviors.”

Cold, bony fingers brushed against the outer folds of Stretch’s pussy, making him choke on a breathless gasp. His ectoflesh felt tender, almost unbearably sensitive, but the light contact also made a yearning shudder run through him. Despite the earlier orgasm, his cunt hadn’t been given the proper stimulation that would allow it to disappear, and the unfulfilled need was starting to turn into a aching cramp.

“I…” Sans’s fingers brushed against him again, and Stretch;s hips bucked mindlessly before he realised that it was only because Sans’s hand was trembling. “I can’t. Not this, G, I can’t-”

“Then don’t,” the doctor said, releasing Sans’s wrist indifferently. “It was only a suggestion. I’m sure the Subject will endure. You would merely be saving him some discomfort.”

Sans’s breathing was loud, almost ragged. He drew his hand back, but slowly, as if the Doctor’s ominous assessment was giving him second thoughts.

“Activate the injector again,” the Doctor ordered. “We won’t be able to proceed to the next phase until his circulatory system has been properly reinforced. We’re already behind schedule since this subject lacks the training and development your brother has undergone to naturally enhance his physical attributes.”

Stretch thrashed weakly, pitiful whimpers pushing past the gag. He couldn’t do that again. It HURT. It hurt _SO MUCH._ He couldn’t take it. He didn’t want it. He didn’t want any of this! Something was leaking from his sockets. He couldn’t tell if it was tears, sweat, or the same disgusting sludge that was creeping from his joints. Sans’s hesitation was even more marked this time, but once again his hand came down on the button and Stretch’s soul ignited in agony.

The pain was incredible, worse than the first time. He could feel his bones spasming, twisting back against the natural direction of the ligaments, contorting in unnatural, agonising shapes. His soul was constricting so tightly he thought it might shred itself on the sphere inside it. He couldn’t breathe. Couldn’t think. Couldn’t exist in his own mind, alongside the pain. It was too large, too consuming. It felt like he was disintegrating, turning to dust in a conflagration of heat and madness.

Until it broke again, though not as abruptly as the first time. Instead of one great and sudden swell, a single spike of pleasure broke through the pain. Then again. Again. Rhythmic and regular, until he could nearly find himself again, his mindless suffering easing as he became dimly aware of his body still twitching and convulsing, but now also rocking desperately at the hips. There was a persistent pressure between his legs, something that stroked firmly against his ectoflesh, delving into the slit of his pussy to tease at the possibility of filling him. His muffled screams stuttered into a carnal groan, because even though he didn’t feel satisfied, the relief was enough to send him tumbling over the edge of climax again with an overwhelming expulsion of wet, vulgar release.

“Fuck…”

It took several long seconds to focus on Sans’s voice. Stretch’s body felt distant, disconnected from that overwhelming experience. It felt like he was outside himself, watching some strange, surreal reality where Sans was lifting his hand from between Stretch’s legs, his fingers coated in orange and black. The horror in his expression was so poignant it was almost hilarious, and Stretch thought he might have laughed if he hadn’t completely lost touch with his physical self.

“Well done,” the doctor approved mindly. “The second treatment appears to have been a success. Subject’s mana-pathways have increased in diameter by another 3.4 percent. Expulsion of excess magic has been successfully facilitated by manual intervention and-”

“Can you just-” Sans took an uneven breath, “-stop talking?”

“It’s important to fully record all outcomes of the experiment, Sans,” the Doctor informed him placidly. “There’s still much work that needs to be done.”

Sans seemed to be swaying slightly in place...or perhaps the entire world was wavering around Stretch, undulating unnaturally as his senses reeled.

“...though perhaps we can take a break to review the results and continue later. You can-”

The words trailed off into insensible non-sense as Stretch’s consciousness finally gave up on trying to make sense of anything and thankfully shut down out of self-defense.

* * *

 

The first tentative brush of consciousness filled him with despair. **_No_**. No, he didn’t want to be awake. No, he didn’t want to be aware. He wanted to sleep and stay forever out of reach of the awful reality that was lurking just on the boundary of cognizance.

“Stretch?”

Sans’s voice seemed very distant, and Stretch didn’t even try to respond to it. He clung fiercely to his current state; not fully awake but not quite able to sink back into oblivion. There was a brief pause -- hopeful or wary, Stretch couldn’t tell -- before Sans gave a quiet sigh, expectation abating and the silence covered back up by the low sound of pouring water.

Stretch didn’t have long to wonder about its cause. A warm spray gently grazed over his wrist, making him flinch. The pressure was gentle, but his bones felt so damn sensitive, especially in the crevices where magic joined them together. The water felt like needles prying into the joints, and Stretch let out a low whimper. He could feel his arm shaking, twitching with uncontrollable spasms, but even if he hadn’t still been tied down he doubted he could have lifted it.

“Easy,” Sans soothed, his voice unexpectedly comforting because if Stretch ignored the slight difference in pitch, Sans sounded almost exactly like Blue did whenever he woke Stretch from a nightmare. The gentle tenderness was unexpected, and almost enough to jar Stretch into wretched, despairing sobs.

But no, he refused to wake up enough for that. Refused to think about it. Instead he lay still, slightly disconnected from his body as Sans worked his way down Stretch’s arm with the water, carefully scraping away the burnt residue between his bones. Stretch supposed he should be grateful to be cleaned -- even by his low standards, being covered in stale sweat and overcharged magic felt disgustingly uncomfortable -- but once his arms were clean he realised the next target of Sans’s attention was going to be his rib cage and that finally jolted him more fully awake.

“Nnnnn,” he wheezed incoherently, expecting to hear only muffled sound, but the incoherent syllable came out unhindered. The gag had come off, probably because there was an excess of residue gumming the joints of his mandible that would need to be cleaned off. Stretch could taste its foul, acrid flavor, but he couldn’t even conjure a throat to try and swallow it down. Even the smallest movements of his jaw made pain spike through his skull, making it nearly impossible to talk. “D...d’nnn…”

“Shit,” Sans muttered to himself, the shadow of his upper body leaning over Stretch. He was too weak to properly focus the magic in his sockets, so all he could make out was the vague, soft shape of Sans’s body. “Hey, buddy, I’m just gonna get you cleaned up. You’ll feel heaps better without all this mess on your bones, trust me.”

_Trust him?_ Hell no. Stretch made a broken sound -- a hiss, a growl and a sob all at once -- and tried to retreat from Sans’s touch, but the cringing movement made all the subdued aches in his body flare back to life with brutal fervor. He cried out, collapsing back against the table, his body wracked by helpless shudders.

It hurt, _it_ ** _HURT_**. Everything hurt. It burned, all through his marrow and his soul, almost unbearable. He could barely hear Sans’s voice over the sheer, consuming intensity of his body’s complaints.

“-gonna be okay, Stretch, it’ll pass soon. Your HP hasn’t dropped, your body just needs to adjust to the treatment. It just stings because your mana line passages have thickened up and your body isn’t used to the increase in magic, but it’ll get better. You’re okay, you’re fine…”

As much as Stretch wanted to reject the soothing intent, he was too afraid and in too much pain to do anything but desperately soak up what little comfort Sans was willing to give him. He could feel tears trying to well up in his sockets, and even that hurt, the fresh magic scalding the corners of his eyes like his veins were still full of lightning. Sans gently swiped them away, either for Stretch’s comfort or his own.

“There you go, feeling better already, see?” Sans offered him a weak smile as slowly his tremors came to a stop. Stretch didn’t actually feel any better, but emotions were just painful and exhausting, readily giving away to fatigue and numbness. “Now I’m gonna clean you up some more, so just...work with me here, all right?”

Sans’s offer was gentle, as if Stretch had any choice in the matter whatsoever. All the other restraints were still in place, so all he could do was lie pliantly and allow Sans to run his small hose over the sticky, obscene stains around his ribs. The surface of the table was recessed from the edges, allowing it to capture all the excess liquid and funnel it into a drain. Stretch focused on the ceiling, his breath coming in short, hitching gasps that resisted his attempts to control and slow them.

“I’m sorry,” Sans said quietly, unexpectedly.

Stretch didn’t look at him. The light on the ceiling flickered softly, emitting a low hum of power that didn’t quite manage to distract him from the way Sans’s phalanges scrubbed away at the interior recesses of his ribs and spine.

“I could tell you that he means well,” Sans continued, voice low. “He wants us all to get out of here. Out of the Underground, but...it doesn’t really matter what he wants. He’s determined to get it. He won’t be stopped. I can’t...stop him. And my bro…”

Stretch really didn’t want to hear it. He turned his head away, trying to make his point without words. Sans laughed, a strained and humorless sound.

“It doesn’t justify anything,” Sans admitted. “I just want you to know...I’ll take care of you as much as I can, okay?”

His hand lingered briefly on the interior of Stretch’s sternum, hovering in the place his soul would be if it were manifested, before he hesitant withdrew.

He continued on his task without saying anything more, and Stretch couldn’t tell if he felt relieved or anguished by the silence.

**Author's Note:**

> There is some small chance that this could be continued. I certainly left it open ended, and with enough dangling plot-threads I didn't get a chance to flesh out. >_>; Leaving comments and asking questions is a good way to let me know if there's any interest for that, so let me know?


End file.
